Apparatuses of the vibratory or oscillating type are known, to convey a metal charge to a container of a melting plant, which is advantageously a melting furnace.
Such known apparatuses provide a segment long enough to pre-heat the metal charge sufficiently, by means of fumes exiting from the furnace, while it is being conveyed.
Each of the known apparatuses comprises a bearing structure on which a conveyor channel is mounted, having a substantially U-shaped cross section or similar.
At least part of the conveyor channel is covered at the upper part by one or more hoods that can define a tunnel into which the fumes exiting from the melting furnace flow, in the direction opposite to that in which the metal charge advances, and carry out the pre-heating.
The conveyor channel is provided along the lateral walls with apertures communicating with suction channels connected to fume suction devices.
The fume suction devices create a depression inside the suction channels and, through the apertures present in the lateral walls of the conveyor channel, take in the fumes of the hoods so that they pass through the metal charge and heat it.
However, Applicant has found that this solution does not obtain the best result possible since the lower and central part of the metal charge is not hit by the hot fumes, or is only partly hit by them, leaving a considerable central zone on the bottom of the conveyor channel which is substantially cold.
A plant of the above type is also known in which the conveyor channel, at its bottom, has apertures to discharge the fumes that are directly connected to the fume suction device. The fumes taken in by the suction device substantially hit the whole metal charge and also affect its bottom portion.
The apertures made on the bottom of the conveyor channel cause fragments of charge to fall inside the suction channels, and therefore they must be cleaned frequently, with the consequent problem of stopping the plant.
Another disadvantage is that parts of the metal charge can obstruct these apertures, thus preventing a homogeneous heating.
Applicant has set himself the purpose of obtaining a more extensive and more homogeneous heating of the metal charge in order to increase the yield of the plant, reducing the energy necessary for the subsequent melting in the melting furnace.
Another purpose of the present invention is to greatly reduce, if not eliminate, problems connected to the maintenance of the plant.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.